PhototropinsĀ areĀ photoreceptor proteinsĀ (more specifically,Ā flavoproteins) that mediateĀ phototropismĀ responses in various species of algae,Ā fungi and higherĀ plants. Note: FlavoproteinsĀ areĀ proteinsĀ that contain aĀ nucleic acidĀ derivative ofĀ riboflavin. These proteins are involved in a w